Various connecting strips or connecting devices have been provided heretofore to make an electrical connection between a contact member associated with the strip or terminal and a conductor which is to be mechanically and electrically secured to the contact member at the terminal.
In early strips or terminal blocks of this type, a screw forming the contact member was tightened to clamp the conductor in place after the conductor had been placed under the head of the screw or between some other portion of the screw and a support. Such arrangements afforded highly effective mechanical locking in combination with a good electrical connection, but were difficult to manipulate and were time consuming to operate.
Solder-lug connections provide still better electrical junctions but often are mechanically insecure. In recent years efforts have been made to provide quick-operating connectors in which a stripped or unstripped end of the conductor is mechanically locked in place and during the locking operation is brought into forceable engagement with a cutting edge of the contact member so that the secured electrical connection is ensured by cutting into the conductor with the contact member.
While devices of this type are available in a variety of forms, this invention is concerned primarily with devices in which the movement of the conductor is effected by a swivel device which carries the conductor end into engagement with the contact element.
For example, in German patent document DE-OS No. 29 15 184, the swivel device forms part of a contact element made from a sheet metal strip and having the shape of a "U" lying on a side with an upper leg disposed above the lower leg. The upper leg carries the connecting wire and by pressing down the free leg, a cutting and clamping terminal projecting upwardly from the lower leg locks against the conductor and holds the free end of the upper leg in a locked position as well as to grip the conductor.
German patent document DE-OS No. 23 55 873 represents an earlier arrangement in which the wires to be connected are inserted into holes in a disk and are pressed into circularly disposed contact elements.
Still another arrangement provides an axially displaceable connector sleeve whose movement causes radially resilient terminals to press into corresponding chambers of a connector body, the conductors previously having been inserted into these chambers to make electrical contact.
These systems are only examples of the prior art techniques which have hitherto been used to lock a conductor mechanically, simultaneously with a cutting or like action to ensure electrical connection.